Exciton localization and the Stokes' shift in undoped InGaN/GaN multiquantum wells

Y. F. Chen, T. Y. Lin, H. C. Yang

    Research output: Contribution to journalConference articlepeer-review

    Abstract

    Optical properties of undoped InGaN/GaN multiquantum wells (MQWs) have been investigated by photoconductivity, photoluminescence, and photoluminescence excitation measurements. We report the first observation of persistent photoconductivity (PPC) in InGaN/GaN MQWs and show that the PPC effect arises from In composition fluctuations in the InGaN well layer. From the analysis of the decay kinetics, the localization depth caused by composition fluctuations has been determined. Compared with the results of complementary absorption and photoluminescence measurements, it is found that the quantum-confined Stark effect due to piezoelectric field and composition fluctuations both exist in the InGaN/GaN MQWs. These two effects are responsible for the photoluminescence Stokes' shift in the InGaN well layers. Here, we provide an unique way to distinguish the individual contribution to the Stokes' shift for the piezoelectric field and composition fluctuations.

    Original languageEnglish
    Pages (from-to)137-142
    Number of pages6
    JournalProceedings of SPIE - The International Society for Optical Engineering
    Volume3938
    Publication statusPublished - 2000 Jan 1
    EventLight-Emitting Diodes: Research, Manufacturing, and Applications IV - San Jose, CA, USA
    Duration: 2000 Jan 262000 Jan 27

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics
    • Computer Science Applications
    • Applied Mathematics
    • Electrical and Electronic Engineering

    Fingerprint Dive into the research topics of 'Exciton localization and the Stokes' shift in undoped InGaN/GaN multiquantum wells'. Together they form a unique fingerprint.

    Cite this